Fill standard field in order (IW31) in dependence of custom field

Hello guys,

I'm looking for a way to fill some fields when creating an order (TA: IW31) automatically in dependence of other fields. In my case I created a custom field ZZBKP which I displayed on enhancement tab in order. When filling this field, the SAP standard field ILART should be filled as well.

At the moment I use exits EXIT_SAPLCOIH_018 / 019 for handling the custom field. Unfortunately in this exit I only have the custom fields in access and not the SAP standard fields of structure CAUFVD.

Is there any possibility (exit, BADI, BTE) to get some standard field of an order filled in dependence of some other field?

Regards
Michael